JPH01113729A - Liquid crystal electro-optic device - Google Patents

Abstract

PURPOSE:To attain good molecular orientation and gap control with high accuracy by simultaneously mixing and using gap control materials consisting of materials having thermoweldability and materials having no thermoweldability and by specifying the average grain size and spraying density thereof. CONSTITUTION:The control materials 5 which do not exhibit the thermoweldability, for example, glass fibers, and the control materials 4 which exhibit the thermoweldability, for example, epoxy particles are simultaneously mixed and used as the gap control materials. The average particle size of the epoxy particles are specified to 1.5-3 times the average grain size of the glass fibers when the average diameter of the glass fibers is 2-8mum. The epoxy particles are sprayed uniformly at 100-150 pieces/mm<2> spraying density and the glass fibers at 10-15 pieces/mm<2>. The good molecular orientation and the gap control with high accuracy are thereby attained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a large screen liquid crystal display panel using ferroelectric liquid crystal.

[Prior Art] In recent years, development of liquid crystal display panels using ferroelectric liquid crystals has been progressing. In ferroelectric liquid crystal display elements, the time response of optical changes that occur when voltage is applied between electrodes attached to the insides of opposing side substrates is largely dependent on the spacing between the substrates, so this spacing is not maintained uniformly. This causes variations in the response time of the liquid crystal, resulting in a significant deterioration in display quality. Furthermore, since the birefringence of liquid crystal is used as a display mode, variations in the spacing between the substrates appear as color unevenness. For this reason, efforts are being made to put into practical use a method in which a gap control material made of a material that does not exhibit heat-fusibility with high dimensional accuracy and a gap control material made of heat-fusibility epoxy particles are mixed together at the same time.

[Problem to be solved by the invention]

However, even if the above method is used, high precision gap control is difficult because the dispersion density of the two types of gap control materials is uncertain.

In particular, in liquid crystal display elements using ferroelectric liquid crystals, display response characteristics, drive voltage characteristics, and color tone may vary, and molecular alignment defects may occur due to the gap control material. gap control was desired.

[Means to solve the problem]

In order to solve the above-mentioned problems, it is preferable to configure the substance that does not exhibit thermal fusibility by using, for example, glass fiber, and the substance that exhibits thermal fusibility by using, for example, epoxy particles, and the average length of the glass fiber is is 2 of the glass fiber average diameter
The average particle diameter of the epoxy particles is preferably 1.5 to 3 times the average diameter of the glass fiber, and the scattering density of the epoxy particles is 100 particles/mm'' to 150 particles/mm''.
Good molecular orientation and highly accurate gap control can be achieved by uniformly dispersing glass fibers at a density of 10 pieces/mm” to 15 pieces/mm”. It is.

The present invention will be explained according to the following examples.

〔Example〕

FIG. 1 shows a cross section of a liquid crystal panel used in the present invention.

On a glass substrate with an area of 310 x 220 mm, an ITO film, which is a transparent conductive film, is formed to a thickness of 1,700 mm by sputtering, and a transparent electrode pattern with a width of 390 μm and a pattern interval of 20 μm is created using photolithography. After forming and coating this electrode with an alignment film ■,
Orientation treatment was performed. As this alignment film, a commonly used organic alignment film can be used, but as will be described later, the effects of the present invention can be more easily obtained with a film that has good adhesion to the heat-fusible gap control material. Therefore, in this example, a polyimide alignment film was used. Next, the average diameter is 2.5 mm and the average length is 1.
A 0 μm glass fiber ■ was mixed in a Freon (CFCf:+) solution at a ratio of 0°2 g/l, and ultrasonic vibration was applied to sufficiently disperse the fiber on the glass substrate on which the transparent electrode was patterned. I sprayed it on. After that, Freon (CFCf3
) The mixture was mixed with a solution and sufficiently dispersed by applying ultrasonic vibration, and then sprayed onto the substrate on which the glass fibers described above had been scattered. At this time, the dispersion density of these gap materials (1) and (2) was adjusted by changing the spraying time. On the other hand, on the opposite substrate, a peripheral seal (■) is formed using a thermosetting epoxy adhesive using a screen printing method, and the two types of substrates are pasted together facing each other, and a uniform pressure of 2 Kg/Cm is applied. Do not add ゛18
It was heated at 0''C for 12 hours to harden and bond the epoxy particles (2) and the epoxy adhesive (2) on the periphery.

The liquid crystal panel prepared as above was filled with ferroelectric liquid crystal ■ (C3-1011 manufactured by Chisso Corporation) by vacuum injection method.
A deflection plate ■ was attached.

In the above method, the distribution density of each of the epoxy particles (■) and the glass fiber (■) is 50 to 100 particles/mm on the A panel.
", 10~15 pieces/mm" and B panel 100~
150 pieces/mm”, 10-15 pieces/mm” and C panel 150-200 pieces/mm”, 10-15 pieces/mm
” and D panel 100-150 pieces/mm2.1-5 pieces/m
m” and E panels 100-150 pieces/mm2.20-25
A liquid crystal display panel was fabricated with a density of 1/mm.

As a result, a BSD panel with high precision gap formation and fewer molecular orientation defects was created. Among them, panel B had the best characteristics and no color unevenness in appearance.

Table 1 below shows examples of varying the distribution density of glass fibers and epoxy particles.

Table 1 In this example, glass fiber was used as the gap control material that does not have heat-fusibility, but it is not limited to this, and even inorganic materials such as alumina and organic materials that do not have heat-fusibility can be used. It was also good.

〔Effect of the invention〕

As explained above, the present invention provides high-precision gap control and reduction of molecular alignment defects in a liquid crystal display panel using ferroelectric liquid crystal, and by implementing the present invention, it is possible to uniformly drive the liquid crystal within the panel. Therefore, display quality can be improved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a liquid crystal display panel used in the present invention. 1.6...Glass substrate 3...Alignment film 4...Gap control material 5 with thermal adhesive properties...
Gap control material 7 that does not have thermal adhesive properties... Peripheral seal

Claims (1)

[Claims] 1. A substrate with a pair of electrodes, at least one of which is transparent, is arranged such that the electrode surfaces thereof face each other, and the gap control material is made of a substance that does not exhibit heat fusibility and has heat fusibility. A liquid crystal electro-optical device comprising: a gap control material made of a substance having a substance having the properties of the substrate; and a gap control material made of a substance having the above-mentioned properties; Device. 2. In claim 1, when the gap control material made of a substance that does not exhibit heat fusibility has an average diameter of 2 to 8 μm, the gap control material made of a heat fusibility substance A liquid crystal optical device in which the average particle size is 1.5 to 3 times the average particle size of a substance that does not exhibit thermal fusibility. 3. In claim 1, the dispersion density of the gap control material made of a substance that does not exhibit thermal fusibility is 10
The gap control material made of a heat-fusible material is uniformly spread at 15 pieces/mm^2 to 15 pieces/mm^2, and the scattering density of the gap control material made of a heat-fusible material is 100 pieces/mm^2 to 15 pieces/mm^2.
Liquid crystal electro-optical device uniformly dispersed at 150 pieces/mm^2 to 150 pieces/mm^2.